Rotary pump or motor



April 7, 1953 w. J. CAREY 2,633,303

ROTARY PUMP OR MOTOR Filed May 22, 1947 v 5 Sheeiis-Sheet l Q INVENTOR;

BY/fW W 3 Sheets-Sheet 2 W. J. CAREY ROTARY PUMP OR MOTOR April 7, 1953 Filed May 22, 1947 INVENTOR.

G v s m April 7, 1953 w, CAREY 2,633,803

ROTARY PUMP OR MOTOR 3 Sheets-Sheet 3 Filed May 22, 1947 Patented Apr. 7, 1953 UNITED STATES PATENT OFFICE ROTARY PUMP R MOTOR William J. Carey, Cleveland Heights, Ohio Application May 22, 1947, Serial No. 749,747

14 Claims.

1 v My present invention comprises a novel and improved construction of rotary fluid pump or motor of the axially sliding vane type generally similar to that of my previously issued Patent No. 2,029,520 issued February 4, 1936.

The principal object of my invention is to provldea pump or motor construction of this general type which is of more simple construction and less expensive to manufacture.

Another principal object of my invention is to provide a pump or motor of this type which is'more eflicient in that it will operate at higher pumping pressures with less wear on the movable parts.

Still another principal object of the invention is to provide means for causing more rapid axial movement of the blades or vanes carried by the rotor so as to reduce the wear on the cam surfaces of the pumping chambers and to enable the opposite ends of the vanes or blades to contact, with the wall of the pumping chamber at an earlier point in the rotational travel of the vanes thereby enabling the pump to maintain higher'pressures.

Another object of my invention is to provide a vane or blade construction and arrangement in respect to the rotor such that the fluid pressures acting upon the blades or vanes when the rotor is rotating are caused to counterbalance slippage at the ends of the blades or vanes and maintain the same in better contact with the wall of the pressure chamber.

In carrying my invention into practice I provide a pump or motor construction of a rotary type in which pumping chambers are provided on both sides of the rotor and the latter has associated with it axially slidable vanes or blades which are shiftable axially of the rotor in rotation thereof so as to act alternately upon fluid introduced to the pumping chambers or zones at opposite sides of the rotor, whereby said vanes or blades are operable to act upon fluid at one side of the rotor to create pressure in one of said pumping zones or chambers and upon expulsion of fluid therefrom to an outlet port are shiftable axially of the rotor to then act upon fluid in the other pressure zone or chamber at the other side of the rotor to create pressure in the latter chamber.

In my new pump or motor construction I utilize a separator member or plate interposed between the heads or sections of the pump housing and this separator member cooperates with the-heads or sections of the pump housing in a novel manner to properly align said heads or sections of the -pump housing. This separator 2 member is further utilized in a novel manner to provide port passages for controlling inlet and outlet of fluid to and from the pumping zones or chambers at opposite sides of the rotor. The separator member is alsoutilized to provide a seat for a by-pass valve arranged in a novel manner in the structure.

In my new pump construction, the pumping chamber is provided with upper and lower walls each having portions parallel with one another and other portions inclined in reference to the plane of rotor and extending from one of said parallel surfaces to the other. Certain of these inclined wall portions constitute cam surfaces acting to shift the blades axially during rotation of the rotor. In previous constructions of this type the contact of the end of the blade with said cam surfaces was productive of considerable wear. In my new pump construction I have provided novel means for causing the pressure of fluid to act upon one end of the blade just as it approaches the cam surface to cause the blade to be shifted axially very rapidly under fluid pressure without reference to the engagement of the blade with the cam surface, whereby the wear upon these surfaces is substantially eliminated or greatly minimized.

'A further novel feature of my invention resides in the construction" and arrangement of the blades with reference to the rotor in such a manner that the fluid pressures created by the pump in operation are caused to act upon the head of the blade during the time that it is positioned within one of the pressure zones 50 as to overbalance the pressures acting in opposite directions at opposite ends of the blade whereby to cause one end of the blade to be maintained more positively in contact with the wall of the pumping zone or chamber.

The pump or motor of my invention embodying the novel features herein disclosed is capable of operation efiiciently at both high and low speed and intermediate speed, that is to say primarily over a speed range from 600 R. P. M. to 1750 R. P. M. approximately and is capable of operating efficiently at both high and low pressures as for example from 10 lbs. per sq. in. to 2,000 lbs. per sq. in.

Examples of low pressure operating uses for which my pump construction is designed are found in fuel oil pumps for home use, gasoline pumps, oil pumps, etc. Examples of uses of my pump construction in high pressure applications are found in operating units for hydraulic operating machinery, etc.

It is notable that the blades or vanes of my pump or motor construction do not move axially during the time that they are subjected to high pressure from all sides but only move axially when the pressure acting upon one end of the blade is released; also it is notable that the fluid pressures in the respective pressure chambers at opposite sides of the rotor are always opposed to one another and thus are neutralized in reference to their reaction upon the moving parts of the pump. These factors substantially eliminate or greatly minimize wear in reference to the pump construction of my invention.

Other objects, advantages and features of the invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings in which- Figure l is a vertical sectional view of a pump or motor embodying my invention, the section being taken substantially on the line l'l of-Figure 3.

Figure 2 is asectional 2-2 of Figure 1.

Figure 3 is a sectional view similar to Figure 2 with rotor removed.

Figure i is a sectional view taken on the line 4-4 of Figure l.

Figure 5 is a developed view of the pumping chamber or interior of the housing showing-the rotor with the vanes or blades thereon in cliagrammatic lay-out for understanding of the cycle of suction and pumping action of the parts.

Figure 6 is a section taken on the line 85 of Figure 3.

Figure '7 is a plan view of the rotor with the blades removed.

Figure 8 is a side elevation of the rotor with the vanes removed.

Figure 9 is a side elevation of the rotor showing one of the vanes assembled thereon.

Figure 10 is a perspective view of one of the vanes or blades.

Now referring to the drawings, it will be seen that my pump comprises any suitable and desired form of driving shaft l upon which is mounted the rotor 2 keyed to the shaft I.

The pump comprises a casing made up of upper and lower sections 3 and 4 of substantially identical construction with the exception that the lower section 4 has a by-pass valve device associated therewith. Permanently associated with the casing sections 3 and 4 are themembers 5 and 6 respectively having the portions 5a and 6a extending within and press fitted into the interior of the casing sections and forming the upper and lower walls of the pumping chamber. The casing sections 3 and 4 preferably comprise metal castings and interposed therebetween is the separator member a with which-the casing sections 3 and t cooperate to maintain proper alignment. For this purpose the casing sections-3 and 4 are provided with shoulder portions 3a and 4a review taken on the line spectively into which fit snugly the inner wall of the annular member I. The casing members or sections 3 and 4 are secured together by means of bolts 8 passing through suitable openings in the annular separator member 1. A cover member 9 screws upon the threaded tubular extension 4b of the lower casing section 4.

The rotor 2 carries blades or vanes 10 which are mounted to slide axially of the rotor and shaft i and are equipped with heads II and i2 which project laterally forwardly from the body of the vane for a special purpose. The vanes 10 are mounted to slide in grooves I3 of the rotor. The heads II and 12- of the vanes are 4 adapted to move into recesses l4 and I5 formed in opposite sides of the rotor and located at the opposite extremes of the grooves i3 of said rotor in which the bodies of the blades are slidably supported. The bottoms of the recesses 14 and 15 form limiting stops for the heads I l and I2 of the blades I0 to prevent actual contact of the ends of the latter with the wall portions of the pumping chamber to eliminate friction between these parts. The formation or" the heads II and i2 and the recesses M and I5 is particularly designed in order to entrap the pressure fluid as the heads enter the recesses, whereby to obtain a cushioning effect derived from the entrapped pressure fluid, this cushioning effect being intended to reduce the impingement or impact of the blade, as actuated by the pressure fluid in a manner to be later pointed out herein.

The formation of the pumping chamber is peculiar in that the flanges 5a and So have their inner faces shaped in a special manner in order to provide upper and lower walls having portions parallel with one another as designated at A and A in the developed view of Figure 5 and other portions inclined in reference to the axis of the rotor as designated B in Figure 5, the incline portions B being sometimes referred to herein as cam surfaces and extending between the parallel surfaces A and A of each flange 5a and 6a. The flanges 5a and ta are formed identically of the same shape as to the inner walls member 6a. The parallel surfaces A and A of each flange member 5a and 6a are also interconnected by curved portions B, these latter portions B being spaced circumferentially from one another, and being located on the opposite side of the rotor and a little to the rear of the inclined surface B of the other flange 5a. or 6a. The cam surfaces B are the portions of the pump chamber wall over which the vanes I!) are riding during their axial shifting action.

The lower casting section 4 is provided with an inlet pipe or conduit it as seen in Figures 2 and 3, whilst the upper casing section 3 is provided with an outlet conduit or pipe H as seen in Figure 4 for outlet of the fluid under the pumping action of the pump.

The pumping chamber defined as to its upper and'lower walls by the inner faces of the flange members 5a and 6a is divided into pumping com- .partments I8 and [9 which are located above and below the rotor as seen in Figure 5. The pumping compartment is is divided into suction and compression zones by means of the vanes or blades 10. The pumping compartment i9 is likewise divided into suction and compression zones by means of the blades or vanes 10. The inlet conduit or pipe l6 supplies thefluid directly into the suction zone of the pumping compartment [9 through. inlet port 2i} which, leads into a space or channel 2! and from said channel '2! through a port 22 into the pumping compartment IS. The channel or space 2! in the lower casing section 4 comprises what might be termed the lower inlet channel and communicates through a port 24 in the annular separator member 1 with an upper inlet channel 25 in the upper casing mem- 'ber 3 as seen in Figure 4. Thus the fluid enterthe inlet port 20 will travel through the upper inlet'channel 25 and thence through the port 26 so as to enter the suction zone of the pumping compartment l8, this suction zone being in-.

blade 10a in Figure 5 extends to outletport 30 which communicates with the upper outlet channel 3| (in upper casing section 3) which in turn communicates through outlet port 32 with the. outlet conduit H. The channel 3| is also in communication through port 33 in the separator member I with the lower outlet channel 34 in the lower casing section4. The pumping compartment l9 has an outlet port 36 which communicates with the lower outlet channel 34. The compression zone of the lower pumping compartment' l9 extends from the outlet port 36 to the left or forward side of any blade momentarily positioned intermediate the ports 22 and 36, the suction zone at such time extending from the right-or rear side of such blade to the suction inlet port 22. The fluid discharged-from the lower compression zone of the lower pumping compartment I9 may pass from the lower outlet channel 34. through the port 33 to theupper outlet channel 3| and thence to the outlet conduit Thus it will be apparent that during the operation of the pump fluid is being continuously introduced to the upper and lower suction zones 21 and 28 above and belowthe rotor 2, from the inlet pipe l6 and that fluid is continuously being discharged from the upper and lower compression zones of the pumping compartments l8 and I9 to the outlet pipe It may be noted that the inlet and outlet channels 2| and 34 of the lower casing section 4 comprise an annular recess in said casing section 4 which is'blocked off by means of the blocking members 31 and 38 so as to dividesaid annular recess into the two separate inlet and outlet channels 2| and 34, respectively. Likewise the inlet and outlet channels 25 and 3| comprise an annular recess in the upper casing section 30f the pump, which annular recess is'blocked off by means of blocking members 39 and 40 to separate the same into the two separate inlet and outlet channels 25 and 3| respectively. The annular separator member 1 serves to close the inner open endsof said recesses'and thus cooperates to provide the separated channels aforesaid and also functions to provide ports 24 and 33, port 24 providing communication between the lower and upper inlet channels 2| and 25, and the port 33 providing communication between the upper and lower outlet channels 3| and 34.

It will be noted that a pressure outlet port 29 leads from the compression zone of the upper pumping-compartment l8 and extends from the forward end of thelcam surface B with its axis at an angle to the axis of the rotor 2 and that the flange member 5a is recessed as at 42 (Figure '5) to provide communication between the upper pressure outlet port 23 and an upper pressure inlet port 43 leading back to the pumping compartment |8 just rearwardly of the cam surface B with respect to the direction of movement of. the rotor, the port .43 having its .axisiparallel to the axis .of the rotor 2'. The pressure inlet port 43' functions, when. a blade ||l comes in register with said pressure inlet port 43 during rotation of said rotor 2, to act upon the head II of theblade Hi, to shift the blade l0 downwardly axially of the rotor 2 with given rapid action so that wear due to contact of the head ll of the blade ID with the cam surface B is substantially eliminated or greatly minimized and the head |2 of the blade l0 iscaused to move into contact with the surface A of the pumping chamber H) at a point rearwardly of that which would otherwise bev the case were the pressure inlet port 43 not provided. This serves to enable the pump to maintain higher pressures.

' Simi1ar1y,,as seen in Figure '5, the lower flange member 6a is recessed as at 44 to provide communication between the pressure outlet port 35 and the pressure inlet port 45. .The pressure outlet port 35 is disposed in a manner corresponding to that described in reference to the pressure outlet port 29 and the pressure inlet port 45 is disposed in a manner corresponding to that described in reference to the pressure inlet port 43, the pressure inlet port 45 functioning in the same manner but acting upon the lower heads l2 of the blades |6 to shift the latter upwardly axially of the rotor 2.

By-pass valve means now to be described is provided for permitting return of fluid from the pressure outlet channel 3| to the suction or inlet channel 2| whenever the pressure becomes excessive. This by-pass valve means includes a port 41 in the annular separator member 1 providing a valve seat for the ball valve member 48 which is normally maintained in seating engagement closing the port 41 by means of the spring 49, the compression of which may be adjusted by means of the spring adjustingscrew 50 provided in a tubularextension member 5| which is interiorly threaded to receive the adjusting screw 50 and which is exteriorly threaded for screwin of the member 5| into the lower part of the lower casing member 4. A screw cover 52 and sealin member 53 are provided for sealing the lower end ofthe member 5|. A passage 54 in the upper housing or casing section 3 provides communication between the pressure-outlet channel 3|. and the port 41 and the porter passage 55 provides communication between the lower" inlet channel 2| in the lower casing section 4 and the port 41 when the valve member 48 is unseated due to excessive pressure. Thus under such pressure conditions fluid is allowedto return from the upper pressure outlet channel 3| to the lower inlet suction channel-2 Operation By reference to Figure 5, the pumping cycle will now be described, bearing in mind that the rotor rotates-in the direction indicated bythe arrows in Figures 2 and 5. Fluid enters the upper pumping-chamber through the suction inlet port 26, and hence the blade |0a which is shown in Figure 5 about midway between the suction inlet port 26 and the pressure outlet port 30, and moving in the direction of the arrow, is sucking fluid into the suction zone 21 and expelling fluid in advance of the blade Illa from a compression zone of chamber l8 through outlet port 30. When the blade Illa arrives opposite the,

accesses? 1.. engages the wall A of the lower pumping com partment I'9-. Meanwhile fluid is entering the lower pumping compartment. I9 through lower suction inlet port 22 and blade I Db which is shown in Figure 5 as just passing suction inlet port 2-2, will upon further rotation of the rotor aftersaid blade IIlb passes port 2-2 create a suction zone 28- to the right of blade Illb and a compression zone in advance of said blade whereby fluid will be sucked intothe lower pumping compart-. ment I9 through port 22 and fluid in advance of. blade Ib will be moved toward and expelled from the pumping compartment I9 through lower pressure outlet port 36:.

Blade Inc is shown in Figure 5 as in a posi! tion just opposite pressure inlet port 45 and upon arriving at this position pressure fluid acting through port 45 upon the lower head I'2' of said blade IIlc will cause rapid shifting of said blade upwardly axially of the rotor 2 so that the head: I I will engage the surface A of the pumping compartment 18.

Thus in the operation of the pump, the rotation of the rotor 2' causes the blades ID. to act alternately upon fluid introduced into the upper and lower pumping chambers or compartments I 8 and f9, whereby fluid is continuously intro-. duced into said pumping compartments and ex-. pelled therefrom under pressure through the pressure outlet ports 30 and 36. It will be. noted that one of the blades I0 is always intermediate the suction inlet andthe pressure outlet of one of the pumping compartments I8 or I9. There is always a high compression zone in advance of one of the blades even at times when the otherblades are either in the process of shifting axially or have not: passed the respective suction inlet port so as to create a compression zone in ad-. vance of such blade. Thus the pump of my construction is capable of maintaining continuous high pressures, and in my construction the compression zones in advanceof the blades are created more rapidly due to the rapid axial shifting action of the blade produced by the fluid pressure at the pressure inlet ports 43 and 45..

- It is notable also that on account of" the construction and arrangement of the blades Ill i-n-V volving the provision of the laterally offstanding heads II and I2 and the fact that these heads are offstanding forwardly of the blades having reference to the direction of rotation of the'rotor, this construction and arrangement of the blades It) enables pressure of fluid in either pumping compartment in advance of the blade to act to create pressure between the rotor 2 and the head of the blade that is in the respective pumping compartment I8 or I9 so as to produce a pressure acting upon the head of the blade overbalancing the pressure slippage acting in opposite directions upon the heads of the blades, with the result that the head of the blade that is in a respective pumping compartment is maintained positively pressed against the wall A of said pumping compartment. It may also be noted that the blades I0 arencver shifted axially when they are under pressure but are only shifted. axially when the pressure atone end of the'blade is relieved, as illustrated by the condition of; the blade We in Figure 5. It. will be apparent that when the blade Illc is positioned opposite the pressure inlet port 45. the pressure at the oppo= site end of the blade has been relieved so that no pressure is acting uponthe head II of the blade. Inc because the head I I is at such time adjacent to. theinlet or: auction port .26.

The construction or my pump is suchthat the. pressures in the upperand lower pumping. chamhere or compartments. are opposed. to one another clue to intercommunication of the inlets and out.- lets therefrom so that the pressures acting upon the parts of the pump are neutralized. in their application thereto and thus wearof.= these par-ts is substantially eliminated or greatly minimized.

It willbe apparent that the pump of my invention disclosed herein is of simple construction which is relatively inexpensive to manufacture and that the separator plate or member I is not only a means to co-operate with. the annular recesses in the upper and lower housing orcasing sections to provide separated inlet and, outlet.

channels: therein and portv passages for inter communication of certain of said channels and a valve: seat for the by-pass valve but also functlons as an aligningmeansfor aligning the upperand. lower casing sections in properalignment with the axis of the drive shaft; 1 of the pump, this alignment being, obtained by cooperation of the annular separator member I: with the. shoulderedportions 3aand 4a of the upper and lowercasing sections 3 and 4 as above. described. Thus:

a positive alignment of the casing sections is; maintained whereby friction in reference to the, rotation of the drive shaft I- is greatly reduced and the wear substantially minimized.

In my type of pump of course, no springs are required for actuation ofthe. blades or vanes and this. eliminates another factor of wear.

The various. factors above. mentioned contributing to the elimination of friction and wear substantiallyreduce the power requirements for operation of my pump and therefore make it highlyefiicient and economical to operate as compared with other pumps of similar capacity;

As seen in Figures 4 and 5, the outlet portv 30 extends through the outer wall of the upper pumping compartment I8; which, outer wall is formed by the upper casing section 3. It will be; noted that the upper outlet port; 30 extends, alongside; of the cam surface B from a point just forwardly of; the; inlet. pressure D0 1 43} to; a point; forwardly of the cam surface. 13;. The port: 30 extends alongside of the cam surface B and downwardly therefrom, the lower) edge; of port; 30- being inclined: for a portionthereof substantiallyparallel. to cam surface 13, as apparent; from the dotted line showing of- Figure 5. The lower inclined edge portionof: port 30 is arranged so that fluid in recess I4. of the rotor willnot be entirely expelled therefrom but some fluid will bev trapped therein until the respective blade ID has substantially reached the forward end of the cam surface B in passing thereover. Similarly the outlet port, 36. from the lower pumping compartment Idextends; through; the outer wall of said lower pumping compartmentformed by the lower casing-section; 4. The port 36 also extends alon side of the cam surf-aceB froma p int: j st forwardly of th inlet pressure port 45 to a point forwardly of the cam surface B. The outlet port 38. extends alongside of the cam surface B and upwardly therefrom, the-upper edge of the port 36 being inclined for a portion thereof substantially parallel to. the cam surface B for the same purpose as described in reference to the corresponding portion of. the outlet port 30, theshapeand arrangement of the outlet port. 36 corresponding to that of outlet port 30.

This arrangement of the. outlet. ports 30 and 361 permits fluid between the heads II or I2 of the-blade t0. and. he. rotor.- t e exp ll d throu h accuses *9 the outlet ports 30 or 36 as said'blades are shifted axially of the rotor in passing over the respective cam surface B. However, due to the arrangement and shape of the ports 35 and 36 preventing expulsion of fluid from the recesses I4 or I5 and permitting some fluid to be trapped therein until the respective blade Ill has substantially reached theforward end of the cam surface B in passing thereover, the axial shifting movement of the blades Illc will be cushioned both in respect to the head of the blade entering itsrespective recess I4 or I5 and also in respect to the impingement of the other head of the blade with the wall surface A. At the same time, in view of the fact that the ports 30 and 36 extend forwardly of the forward edges of the cam surfaces B, it is insured that substantially all of the fluid will be expelled from the respective recess I4 or I5 by the time that the blade in reaches the forward end of the cam surface B in passing thereover so that full-axial shifting movement of the blade will take place. The result of the provision of the outlet port 30 and 35 as described and of the provision of ,the pressure inlet ports 43 and 45 is to accomplish more rapid and positive shifting action of the blade Ill while at the same time cushioning this shifting action so that wear due to impact of the blade heads with the rotor and with the wall surfaces A is reduced as much as possible.

,It will be notedthat the means of communication between the outlet port 29-and the pressure inlet port 43, and also between the outlet port 35 and the inlet pressure port 45 provides segregated passages leading to the respective pressure inlet ports 43- and 45 whereby the fluid in these segregated passages or channels is segregated from the main outlet channel provided by the outlet ports 35 and 36. The provision of these segregated channels leading to the pressure inlet ports 43 and 45 enables pressure to be built up in said channels and to act through pressure inletports 43 and 45 upon the ends of the blades m in the manner described.

' It will be noted that the wall surfaces Aof both the upper and lower pumping compartments I8 and I9 are provided with recesses 60 and GI located just rearwardly of the cam surfaces B and extending from the rear end of said cam surfaces to a pointrearwardly of the inlet pressure port 43 and 45 respectively, the front to rear length of the recesses 66 and BI being about equal to the front to rear length of the heads I I and I2 of the'blades If]. The recesses 60 and BI extend from side to side the entire width of the respective pumping compartment I8 or I9 radially of the axis of shaft I,-the crosswise width of said recesses 60 and 5| being equal to the crosswisewidth of the blades I6. Recesses BI] and BI respectively communicate with ports 43 and 45.

From the foregoing it will be understood that the area of said recesses 6i} and BI exposed to the end of the blade head when the latter is positioned over said recess is about equal to the area of the surface of the outer end of the blade head, or at least greaterthan the effective: area of the underside of the blade head exposed to the pressure of fluid in advance of the blade acting to maintain the:blade head in contact with wall surface A. The provision of these recesses 69 and GI permits the inlet pressure ports 43 and 45 to apply "fluid pressure to the outer ends of the blade heads over substantially the entire area of the surface of. the outer ends of blade heads; For -examp e',-When the bladelilo arrives at position in its-rotation as illustrated in Figure 5, the pressure force of fluid applied by the port 45 and recess GI to the head I2 of the blade I00 will be a greater pressure force than that exerted upon the head I2 of the blade Ito between the rotor and the head I2, whereby the pressure force applied to the head I2 of the blade I 0c by the port 45 tending to move the blade I00 axially upwardly will be greater than the pressure tending to resist such axial movement.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States, is:

1. A pump of the class described comprising, in combination, a driveshaft, a rotor mounted thereon, blades movably mounted on said rotor and shiftable axially of the rotor incident to rotation thereof, a pumping chamber enclosing said rotor and blades and comprising oppositely disposed casing sections having recesses therein opening toward one another, and an annular separator member interposed between said casing sections and'cooperating therewith to separate said recesses, said recesses comprising inlet and outlet channels in each ofsaid casing sections, said separator member having ports therein for communication between the inlet channels in both casing sections at opposite sides of the rotor and between'the outlet channels in both casing sections at opposite sides of the rotor, means providing communication between said channels andthe pumping chamber, said blades being axiallyshiftable. relative to said rotor alternately into working contact with first one wall and thenanother'wall of said chamber, and cam means at opposite ends of the pumping chamher and having; running clearance with the ends of the rotor and the'blades during axial shifting of the blades as aforesaid.

2. A pump of the class described comprising, in combination, a drive shaft, a rotor mounted thereon, blades movably mounted on said rotor and shiftable axially of the rotor incident to rotation thereof, a pumping chamber enclosing said rotor and blades and comprising oppositely disposed-casing sections having recesses therein openingtoward one ,another, and an annular separator member interposed between said casing sections and cooperating therewith to separate said recesses, said recesses comprising inlet and outlet channelspin each of. said casing sections, saidseparator member having ports therein for communication between the inlet channels in both casing'sections at opposite sides of the rotor and between the outlet channels in both casing sections at-opposite sides of the rotor, means providing communication between said channels and the pumping chamber, said separator member having a'port therein for communication between saidinlet and outlet channels, valve means includinga valve member cooperable with the latter port to control communication therethrough, said blades being axially shiftable relative-to said rotor alternately into working con- .;tact with first one wall and then another wall 1-1 tation thereof, apumping chamber enclosing said rotor and blades and comprising oppositely disposed casing sections having recesses therein opening toward one another, and an annular separator member interposed between said casing sections and cooperating therewith to separate said recesses, said recesses comprising inlet and outlet channels in each of said casing sections, said separator member having ports therein for communication between the inlet channels in both casing sections at opposite-sides of the rotor and between the outlet channels in both casing sections at opposite sides of the rotor, means providing communication between said channels and the pumping chamber, saidseparator member having a port therein for communication between said inlet and outlet channels, valve means including a valve member cooperable with the latter port to control communication therethrough, said valve member being operative to move to open position upon a predetermined pressure existing in selected portions of said recesses, said blades being axially shiftable relative to said rotor alternately into working contact with first one wall and then another wall of said chamber, and cam means at-opposite ends of the pumping chamber and having running clearance with the ends of the rotor and the blades during axial shifting of the blades as aforesaid.

4. In a pump of the class described, in combination, a rotor, a pumping chamber in which said rotor operates, blades'mounted in said rotor and axially movable relative thereto, said blades having heads forwardly oifstanding therefrom with respect to the direction of movement, and when said blades are shifted axially in either direction, one head of each blade being axially spaced from the rotor, whereby pressure fluid in advance of each blade will act upon the head thereof axially spaced from the rotorto maintain said head in contact with the respective wall of the pumping chamber while said head is in a compression zone of saidchamber, said wall having parallel portions and an inclined wall portion therebetween, the blades being arranged to shift axially while passing over said inclined wall portion, said chamber having an outlet port disposed alongside of saidinclined wall portion and arranged so that fluid is trapped between :said head and the rotor during the shifting movement until the blade substantially reaches the forward end of said inclined'wall portion.

5. In a pump of the class described, in combination, a rotor, a pumping chamber in which said rotor operates, blades mounted in said rotor and movable axially of said rotor alternately into working contact with flrstone wall and then another wall of said chamber, said blades having heads forwardly offstanding therefrom "with respect to the direction of movement thereof and when said blades are shifted axially in either direction, one head of each blade being axially spaced from the rotor, whereby pressure fluid in advance of each blade will act upon the 'head thereof axially spaced from-therotor to maintain said head in contact with therespective wall of the pumping chamber while said head is in a compression zone of said chamber, the area of said head acted on by fluid pressure in advance thereof being suiflcient to provide a-fluidpressure greater than the pressure of fluid slippage acting on the portion of the head engaging the wall of the chamber, said wall is provided with a recess extending from side to side of said chamber, the latter having an outlet port and. a pressure inlet port communicating with said outlet port and with said recess for applying fluid pressure to said head of the'blade in a direction opposed to the direction of action thereon of the fluid in advance of the blade, the said recess being dimensioned and arranged to apply to the blade head a greater total fluid pressure force tending to move the blade axially than the fluid pressure force resisting such movement.

6. In a pump of the class described, in combination, a rotor, a pumping chamber in which said rotor operates and comprising compartments on opposite sides of the rotor, each com partment having a suction inlet port, blades mounted in and extending through said rotor and axially movable relative thereto to engage alternately, first one end wall of said pumping chamber in one of said compartments, and then the opposite end wall of said chamber in the other of said compartments, each compartment having a suction zone and a pressure zone, and means comprising a pressure inlet port arranged in the pressure zone of each compartment with its axis parallel to the axis of the rotor for applying fluid pressure to said blades in a direction parallel to the axis of the rotor to shift the'bl-ades axially of the rotor, said pressure inlet ports each being located in its respective pumping compartment at a point opposite the respective suction inlet port of the other pumping compartment so that when fluid pressure therefrom actsupon one end of a blade, the other end of that blade will be located in a suction zone of the other compartment.

7. In a pump of the class described, in combination, a rotor, a pumping chamber in which said rotor operates, and comprising pumping compartments on opposite sides of the rotor, each compartment having a suction inlet port, blades mounted in and extending through said rotor and axially movable relative thereto to engage alternately first one end wall of said pumping chamber in one of said compartments and then the opposite end wall of said chamber in the other of said compartments, each compartment having a suction zone and a pressure zone, each compartment having an outlet port and a pressure inlet port communicating with said outlet port, and said'pressure inlet port being arranged in the pressure zone of each compartment with it axis parallel to the axis of the rotor to apply fluid pressure to said blades in a direction parallel to the axis of the rotor to shift the blades axially of the rotor, said pressure inlet ports each being located in its respective pumping compartment at a point opposite the respective suction inlet port of the other pumping compartment so that when fluid pressure therefrom acts upon one end of a blade, the other end of that blade will be located in the suction zone of the other compartment.

.8. In a pump of the class described, in combination, a rotor, a pumpingchamber in which said rotor operates, and comprising pumping compartments on opposite sides of the rotor, each compartment having a suction inlet port, blades mounted in and extending through said rotor and axially movable relative thereto to engage alternately, first one end wall of said pumping chamber in one of said compartments, and then the opposite end wall of said chamber in the other of said compartments, each compartment having a suction zone and a pressure zone, each compartment having an outlet port having its axisdisposedat-an angle tothe axis of said rotor assets "and themouth-of said outlet port positioned in the path of flow' of fluid from said compartment, and a pressure inlet port communicating with said outlet port, and said pressure inlet ports being arranged in the pressure zone of each compartment with its axis parallel to the axis of the rotor to apply" fluid pressure to said blades in a direction parallel to the axis of the rotor to shift the blades axially of the rotor, said pressure inlet ports each being located in its respective pumping compartment at a point opposite the respective suction inlet port of the other pumping compartment so that when fluid pressure therefrom acts upon one end of a blade, the other end of that blade will be located in the suction zone of the other compartment.

9. In a pump of the class described, in combination, a rotor, a pumping chamber in which said rotor operates, and comprising pumping compartments on opposite sides of the rotor, each compartment having a suction inlet port, blades mounted in and extending through said rotor and axially movable relative thereto to engage alternately first one end wall of said pumping chamber in one of said compartments and then the opposite end wall of said chamber in the other of said compartments, each compartment having a suction zone and a pressure zone, said walls each having parallel portions and an inclined portion therebetween, the blades being arranged to shift axially while passing over said inclined wall portion, and means comprising a pressure inlet port in the pressure zone of each compartment disposed immediately rearwardly of said inclined wall portion with respect to the direction of movement of the rotor, said pressure inlet ports being arranged with their axis parallel to the axis of the rotor for applying fluid pressure to said blades in a direction parallel to the axis of the rotor to shift the blades axially of the rotor, said pressure inlet ports each being located in its re spective pumping compartment at a point opposite the respective suction inlet port of the other pumping compartment so that when fluid pressure therefrom acts upon one end of a blade, the other end of that blade will be located in the suction zone of the other compartment.

10. In a pump of the class described, in combination, a rotor, a pumping chamber in which said rotor operates and comprising pumping compartments on opposite sides of the rotor, each compartment having a suction inlet port, blades mounted in and extending through said rotor and axially movable relative thereto to engage alternately first one end wall of said pumping chamber in one of said compartments and then the opposite end wall of said chamber in the other of said compartments, each compartment having a suction zone and a pressure zone, said walls each having parallel portions and an inclined portion therebetween, the blades being arranged to shift axially while passing over said inclined wall portion, each compartment having an outlet port in said inclined wall portion and a pressure inlet port communicating with said outlet port, and said pressure inlet port being arranged in the pressure zone of each compartment with its axis parallel to the axis of the rotor to apply fluid pressure to said blades in a direction parallel to the axis of the rotor to shift the blades axially of the rotor, said pressure inlet ports each being located in its respective pumping compartment at a point opposite the respective suction inlet port of the other pumping compartment so that when fluid pressure therefrom acts upon one end of a blade,the other end of that blade will'be located in the suction zone of the othercompartment.

11. In a pump of the'class described, in combination, a rotor, blades movably mounted therein and shiftable axially of the rotor incident to rotation thereof, a pumping chamber enclosing 'said rotor and blades and comprising oppositely disposed casing sections having recesses therein opening toward one another, and an annular separator member interposed between said casing sections and cooperating with said recesses to close the open sides thereof, said recessescomprising inlet and outlet channels in each of said casing sections, said separator member having ports therein, one of said ports providing communication between the inlet channels in both casing sections, and another of said ports providing communication between the outlet channels of both casing sections, and cam means at opposite ends of the pumping chamber and having running clearance with the ends of the rotor and the blades during axial shifting of the blades as aforesaid, said casing sections comprising said pumping chamber providing a respective pumping compartment on each side of said rotor, an inlet port for each pumping compartment commuicating with the inlet channel of the respective casing section, and an outlet port for each pumping compartment communicating with the outlet channel of the respective casing section, said blades being axially shiftable relative to said rotor alternately into working contact, first with the wall of one pumping compartment and then with the wall of the other pumping compartment, whereby each blade effects pumping action alternately in said compartments.

12. Ina pump of the class described, in combination, a rotor, a pumping chamber in which said rotor operates, said chamber comprising separated pumping compartments on each side of said rotor, each compartment having a suction inlet port, blades mounted in said rotor and axially shiftable relative thereto for engagement of opposite ends of said blades alternately with opposite ends of said pumping chamber, means providing communication between said pumping compartments, and cam means at opposite ends of the pumping chamber and having running clearance with the ends of the rotor and the blades during axial shifting of the blades as aforesaid, and means comprising a pressure inlet port associated with each pumping compartment and located just rearwardly of the cam means with respect to the direction of movement of the rotor for applying fluid pressure to the end of the blade positioned therein in a direction parallel to the axis of the rotor to shift the blades axially of the rotor, said pressure inlet ports being arranged with their axes parallel to the axis of the rotor, said pressure inlet ports being each located in its respective pumping compartment at a point opposite the respective suction inlet port of the other compartment so that when fluid pressure from a respective pressure inlet port acts on one end of the blade, the other end of said blade will be positioned in the suction zone of the other compartment.

13. A pump as claimed in claim 12, wherein said last means also comprises a pressure outlet port for each pumping compartment communicating with a respective pressure inlet port.

14. In a pump of the class described, in combination, a rotor, a pumping chamber in which said rotor operates and comprising pumping 15 compartments on opposite sides of therotor, blades mounted in and extending through said rotor and axially movable relative thereto to engage alternately first one end wall of said pumping chamber in one of said pumping compartments and then the opposite end Wall of said chamber in the other of said compartments, each compartment having a suction zone and a pressure zone, each compartment having a suction inlet port, and outlet port and a pressure inlet 10 port communicating with said outlet port, and said pressure inlet port being arranged in the pressure zone of each .compartment with its axis parrallel to the axis of the rotor to apply fluid pressure to said blades in a direction parallel to the axis of the rotor to shift the blades axially of the rotor, said pressure inlet ports each being located in its respective pumping compartment at a point opposite the respective suction inlet port of the other pumping compartment, so that when fluid pressure therefrom acts upon one end of a blade, the other end of that blade will be located in the suction zone of the other com- '16 pertinent, said walls each havin a r c s e nding transversely of said chamber with respect to the direction of movement of the blades rotationally relative thereto, each pressure inlet port communicating with the respective recess.

WILLIAM J. CAREY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 750,219 Von Pittler Jan. 19, 1904 15 2,029,520 Carey Feb. 4, 1936 2,311,162 DuBois Feb, 16, 1943 2,493,478 Dinesen et al Jan. 3, 1950 FOREIGN PATENTS 20 Number Country Date 172,602 Germany July 7, 1906 203,342 Great Britain Jan. 24, 1924 .370 France Apr. 1, 1922 

